1.         About 87% of lung cancer cases are caused by cigarette smoking in American (1). However, global statistics estimate that 15% of lung cancer in males and 53% in females (25% in all cases) are not attributable to cigarette smoking(2). In Europe and North America, about 10–15% of lung cancers occur in never smokers. By contrast, about 30–40% of lung cancers occur in never smokers in Asian countries(3).

同一组数据的不同解读：

支持吸烟导致肺癌：87%的肺癌与吸烟有关（美国数据）

否定吸烟导致肺癌：15%的男性肺癌与53%的女性肺癌与吸烟无关（全球数据）

2.        The causal relationship between smoking and lung cancer is well established with a 10- to 20-fold increased risk of lung cancer in smokers compared with never smokers(4). Among male smokers, the lifetime risk of developing lung cancer is 17.2%; among female smokers, the risk is 11.6%. This risk is significantly lower in nonsmokers: 1.3% in men and 1.4% in women(5).

同一组数据的不同解读：

支持吸烟导致肺癌：吸烟使男性患肺癌的风险增加12倍，使女性患肺癌的风险增加7倍；

否定吸烟导致肺癌：只有五分之一的吸烟者会得肺癌

1.     American Cancer Society. Tobacco use. In: Society AC, editor. Cancer facts & figures 2001. Atlanta, GA: American Cancer Society; 2001.

2.     Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer statistics, 2009. CA Cancer J Clin. 2009 ; 59:225-49.

3.     Toh CK, Lim WT. Lung cancer in never-smokers. J Clin Pathol. 2007;60:337-40.

4.     Brownson RC, Alavanja MC, Caporaso N, Simoes EJ, Chang JC. Epidemiology and prevention of lung cancer in nonsmokers. Epidemiol Rev. 1998;20:218-36.

5.     Villeneuve PJ, Mao Y. Lifetime probability of developing lung cancer, by smoking status, Canada. Can J Public Health. 1994;85:385-8.